I have recently completed a microphone shootout on some piano/flute material where i tested ORTF pairs of Audio Technica AT4051s, Beyer MC930s, Neumann KM184s, and an inexpensive set of Avantone CK-1s.
In the past, I ihave successfully used KM184s as spots on piano and pedal harp, but often found the 184s to be a tad bright and thin as a main pair. This test, with a newly acquired pair of older KM184s, came out very different from what i was expecting - the 184s offered a robust and full range representation of the performance, with a wonderfully silky top end, and was perhaps my favorite ORTF pair within the test group of mics. with just a touch of EQ, the 184s become even nicer.
It made me wonder if there is, perhaps, a slight difference between the early KM184s and the newer 184s? At any rate, the 184s have earned a new level of respect from me, and I will be using them as my main ORTF pair for an upcoming flute and pedal harp CD project.